3D Printed Radiation Patterns

Radiation patterns for antennas can be utterly confusing, especially when presented in two dimensions, as they usually are. Fear not, [Hunter] has your back with 3D printed and color-coded radiation patterns.

In the field of antenna design, radiation patterns denote the relationship between the relative strength of radio waves emitted from antennas and the position of a receiver/transmitter in 3D space. In practice, probes can be used to transmit/receive from documented locations around an antenna while recording signal intensity, allowing researchers and engineers to determine the characteristics of arcane antennas. These measurements are normally expressed as two-dimensional slices of three-dimensional planes. Naturally, this sometimes (often) complex geometry is difficult for all but the most spatially inclined to mentally conceptualize with only the assistance of a 2D drawing. With computers came 3D models, but [Hunter] wasn’t satisfied with a model on a screen: they wanted something they could hold in their hands.

To that end, [Hunter] simulated several different antenna structures, cleaned up the models for 3D printing, and 3D printed them in color sandstone, and the end result is beautiful. By printing in colored sandstone through Shapeways, [Hunter] now has roughly walnut-sized color-coded radiation patterns they can hold in their hand. To save others the work, [Hunter] has posted his designs on Shapeways at Ye Olde Engineering Shoppe. So far, he has a horn antenna, dipole, inset fed patch antenna and a higher order mode of a patch antenna, all of which are under 15.00USD. Don’t see the antenna radiation pattern of your dreams? Fret not, [Hunter] is looking for requests, so post your ideas down in the comments!

Further, beyond the immediate cool factor, we can see many legitimate uses for [Hunter’s] models, especially in education. With more and more research promoting structural rather than procedural learning, [Hunter’s] designs could easily become a pedagogical mainstay of antenna theory classes in the future. [Hunter] is not the only one making the invisible visible, [Charles] is mapping WiFi signals in three dimensions.

Would be illustrative to see an isotropic pattern and that same pattern when deformed due to placement on a mast or towers of various widths, and also variations based on side- or top-mounted positions. Mounting and tower dimensioning can make huge differences in actual radiation patterns!

As far as I can see, [Hunter] provides NO explanation/reference about where the pattern data came from, yet he charges MONEY for the results in 3D print. This is from my examination of of BOTH his Shapeways For-Sale page and his related YouTube video.

Unless [Hunter] is taking the data from a Very Expensive professional EM-Analysis application that costs thousands of dollars per-seat for a license, the pattern data he used VERY likely came from one of many free/open-source NEC applications. For example:

Shapeways charges 8 to 9 dollars for a print that he is charging $10. So he is making a few dollars per purchase at most. He did put in work to create them, and I doubt he will sell hundreds.
Are you angry that he might get some beer money off of his effort?

He appears to subscribe to the Stallman philosophy that everyone should do work for the good of mankind, give away everything for free and eat the cost, and survive by eating their toenails.

I, for one, don’t mind if the tools are free. Many of the best tools are. Nothing’s preventing angry people from making their own printable RF fields, and the person selling the models is adding a modest upcharge to cover his time and effort. The entrepreneurial, capitalist spirit.

I’m a binary-loving embedded systems designer working at a company that manufactures RF equipment, mostly waveguide switches. These sorts of visual aids really help when I’m feeling my way through the black magic that I have to work with, far outside the cleancut world of digital logic and Assembly.

Excellent application of 3D printing. I’d love to see the interiors of the prints, like the Visible Human Project, that anatomy exhibit with a cadaver cut into thin slices.